An image forming apparatus may generally operate to form an image on a print medium. Depending on an image forming method, the image forming apparatus may generally be classified as an electrophotographic printer, which forms an image on a print medium through a series of processes, including charging, exposing and developing an electrostatic latent image, and transferring and fusing of the developed image onto a print medium; an inkjet printer, which forms an image by jetting ink through a nozzle; or a thermal transferring printer, which uses a thermal print head.
An image forming apparatus may generally require the use of a rotating body, such as, for example, an image bearing body and a transfer roller, to form an image on a print medium. To secure uniform image quality, the rotating velocity of a rotating body should desirably be kept consistent (i.e., without any fluctuation).
An image forming apparatus may generally include driving power transmitting mechanisms, such as a gear, a belt, a chain, and the like, to transmit rotating power of a rotating shaft of a driving motor to the rotating body. However, unfortunately, even if a driving shaft of the driving motor rotates at a consistent rate, the rotating velocity of the rotating body may fluctuate due to the deviations, due to the allowed fabrication/assembly tolerance, of the power transmitting mechanisms themselves. An image forming apparatus with improved velocity control of the rotating body is thus desired.